Laminated-ring and multiple internal-roll mill



July 7, 1953 M. FRISCH ETAL LAMINATED-RING AND MULTIPLE INTERNAL-ROLL MILL 5 Sh eetS-Sneet 1 Filed April 19, 1949 Zinnmtor MART/N FRISCH I attorney July 7, 1953 I M. FRISCH ETAL 2,644,643

' LAMINATED-RING AND MULTIPLE INTERNAL-ROLL MILL Filed April '19, 1949 5 Sheets-Sheet 2 /2 llm I I s y 7. 53 M. FRISCH ETAL w 2,644,643 LAMINATED RING AND MULTIPLE INTERNAL-ROLL MILL Filed April- 19. 1949 s sheets-sheet :s

E'YR a l 2: 225112523 It:

3nventpts MART/N fie/Jon July 7, 1953 M. FRISCH Emu; 2,644,643

LAMINATED-RING AND MULTIPLE INTERNAL-ROLL MILL '5 Sheets-Sheet 4 Filed April 19, 1949 LLLLLLl Gorneg July 7, 1953 M. FRISCH ETAL RING AND MULTIPLE INTERNAL-ROLL MILL 5 She ets-Sheet 5 LAMINATED- Filed April 19, 1949 Patented July 7, 19 3 LAMINATED-RING AND MULTIPLE INTERNAL-ROLL MILL Martin Frisch, New York, and Gilbert (3-. Whitney, Jr., Dansville, N. Y.,assignors to Foster Wheeler Corporation, New York, N. Y., a corporation of New York Application April 19, 1949, Serial No. 88,412

21 Claims.

This invention relates to pulve'ri'zers or pulverizing mills for grinding or crushing ores, fuels, minerals and various other types of materials. More particularly, theinvention pertains to improvements in mills of the ring and roller type wherein the material is crushed and pulverized by action of the rings and rollers and the pulverized product is delivered to a point of use or storage by a fluid carrier such as a stream of air.

It is an object of the present invention to provide a mill of high pulverizing' efiiciency and low power consumption.

Another object of the invention is to provide a pulverizing mill which does not require mechanical feeding devices.

A further object of this invention is to provide a pulverizing mill in which the output rate is readily controlled by varying the flow of fluid carrier which fluid carrier may be heated for the drying of wet materials while being pulverized 0r cooled to prevent the overheating of materials which tend to soften.

A still further object of the invention is to provide a pulverizer in which the size of the material fed thereto is not critical and in which relatively coarse material may be pulverized.

The present invention provides a pulverizer wherein material to be crushed is fed into crush-- ing compartments by gravity and is crushed by extensions on a gravity loaded roller and by lugs on the outer peripheral surface of a plurality of laterally adjoining rings having lateral and rotative movement in relationship to one another. The gravity loaded roller is supported on the inner peripheral surface of said rings which rings are, in turn, supported and driven by a driving roller or rollers. The driving rollers are engaged by the rings at slightly different diameters and are, therefore, rotated at slightly different speeds. Rotation of the rings also rotates said gravity loaded roller. As the gravity loaded roller rotates, lugs on the extensions thereof break the pieces of material fed into the crushing compartments and project the broken pieces in many directions within the mill. The projected pieces return by gravity into the crushing compartments until material in said compartments is reduced to such fineness that it becomes fluidized. Lugs on the outer periphery of the rings plowing through the fluidized material sustain the fluidization, cause further disintegration of material, and continuously project the crushed fine material in several directions in the mill. The fluidize'ol material in the crushed compartments-overflows onto the inner surface of the rings and is 2 centrifuged and transported in a thin ribbon of material which is squeezed between the adjoining side surfaces of the ring and between the inner periphery of said rings and the rollers. The high pressure thus developed on the ribbon of material continuously forces and squeezes material between adjacent side surfaces of adjoining rings which due to their relative speed of rotation, mull and rub the particles together until they become extremely fine. This extremely fine material is ejected radially from between the rings and is entrained by a gas or air stream and carried through a classifier wherein any oversize material is rejected and returned to the crushing compartments and the fine material is carried to a point of use or storage.

The invention will be understood from the following description when considered in connection with the accompanyin drawings forming a part thereof and in which:

Fig. 1 is a vertical sectional view of a pulverizer of one embodiment of the invention taken on the line [-1 of Fig. 2;

Fig. 2 is a vertical sectional view taken on the line 2--2 of Fig. l;

I Fig. 3 is a plan view taken on the line 3-3 of Fig. 1;

Fig. 4 is a sectionalview taken on the line 44 of Fig. 2;

Fig. 5 is a vertical sectional view on broken line section 5--5 of Fig. '2, the upper portion being swung into the plane of projectionof pulverizing elements as shownin Fig. 1.

Fig. 6 is a view similar to Fig. 5 but of another embodiment of the pulverizing elements;

Fig. 7 is a view similar to Figs. 5 and 6 but of a further embodiment of the pulverizing elements;

Fig. 8 is a view similar to Figs. 5, 6 and '7 but of a still further embodiment of the pulverizing' elements;

Fig. 9 is a side view Fig. 6;

Fig. 10 is a side elevational View of a portion of another embodiment of the invention with parts thereof broken away and taken on the line 9-9 of Fig. 11 is a view similar to Fig. 10 but of a further embodiment of the invention.

Like reference numerals refer to like parts throughout the several views.

Referring to the drawings, the pulverizer or pulverizing mill of the present invention comprises a cylindrically-shaped vertically extending casing H) closed at the bottom by a. bottom plate H and at the top by a curved top plate !2. The

3 casing, as shown in Figs. 1 and 3, is divided vertically into two sections one section having a flange Ill and the other a flange II)" which flanges are bolted together. In this manner, one portion of casing may be removed from the other to expose the pulverizing elements hereinafter described. Ring and roller pulverizing or grinding elements are positioned in the lower portion of easing I 9. As shown in Figs. 1 to 4, a pulverizing ring assembly which comprises a plurality of laterally adjoining rings I3 forming a laminated ring assembly is positioned within the easing in spaced relationship to bottom plate I I and in the central portion thereof in spaced relationship to the inner periphery of the casing laterally of the ring assembly and also as the periphery thereof. The assembly is so positioned in the chamber as to turn on a horizontally extending axis. The rings in said assembly have relative rotative and lateral movement in relationship to one another and also have a plurality of spaced lugs I4 extending radially from the outer periphery thereof. The rings of said group, as shown in Figs. 1 to 6, are of decreasing inside diameter from the outer ring at opposite sides of the assembly inwardly to the central portion of the group and are supported on driving rollers I5 and I6 which rollers have outer rims I1 and I8. The inner peripheral edge of the rings are of substantially semi-circular shape in cross-section so that a substantially V-shaped groove I3, the apex of which points toward the outer periphery of the ring, is formed between adjacent rings. The outer periphery of rollers I5 and I6 is of decreasing diameter from said rims inwardly to a central point so as to thereby form a substantially double frusto-conical-shaped peripheral surface I9 thereon in which the apices of said cones abut one another. With this form of roller, there will be a normal tendency of the rings I3 of the assembly tobe laterally urged toward the center of the ring assembly, as will hereinafter be fully described. Roller I5 is mounted on drive shaft so as to turn therewith, while roller I6 is mounted on drive shaft 2| to turn therewith. The drive shafts 20 and 2| extend transversely of the chamber within casing- I6 in a horizontal plane and are mounted at the opposite ends thereof in bearings 23 and 24 which bearings are located in casing ID.

A gravity loaded crushing roller 25 is supported by the ring assembly in the lower portion thereof. Roller 25 has opposite side rims 26 and 21 spaced apart substantially the same distance as rims I1 and I8 of rollers I5 and I6 and also has extensions 28 and 29 which projectaxially thereof into crushing compartments 30 and 3| which flank the ring assembly. Roller 25, in the form of the invention shown in Figs. 1 to 5, has a peripheral surface 25 of the same shape as peripheral surface IQ of rollers I5 and I6. Extensions 28 and 29 have a plurality of radially extending lugs thereon. Crushing compartments 30 and 3| have curved bottom plates 32 and 32 which are curved on ahorizontal axis extending in a horizontal plane parallel to the axis of rotation of rings I3 and rollers I5, I6 and 25, said plates engaging the inner periphery of easing ID at the opposite ends and along one side of the plates. Plates 32 and 32 are in spaced relationship with bottom II of casing 10 in the crushing compartment portions thereof, plate 32" engaging bottom plate I I in the central portion beneath the ring assembly thereby forming a trough 33 beneath said assembly.

Vertically extending feed chutes 34 and 35 flank the ring assembly adjacent one end thereof and communicate with crushing compartments 30 and 3| respectively from bottom plates 32 and 32 upwardly through the pulverizing chamber and outwardly thereof through top plate I2. The chutes 34 and 35 have outlet openings at a level substantially even with the top of roller 25, said outlets facing parallel to the ends of the ring assembly. The passage of material from chutes 34 and 35 through the outlet openings into compartments 36 and 3| is controlled by guillotine gates 36 and 31 respectively, which gates are raised or lowered by means of cam rods 38 and 39 respectively extending outwardly of casing I0.

In the form of the invention shown in Figs. 1 to 4, a stream of air is caused to flow through the mill by means of an exhauster 40 positioned above the ring assembly in substantial vertical alignment therewith in the upper central portion of the mill. Exhauster 49 comprises a plurality of radially extending blades 4| mounted on a shaft 42 so as to turn therewith. The shaft 42 extends ina horizontal plane parallel to the horizontal plane in which rollers I5, I6 and 25 rotate. Blades 4| are enclosed in a housing 43 comprising a curved end plate 44 and spaced opposite side plates 45 and 46 formin a chamber 4'! therebetween. The chamber 47 formed within housing 43 is in communication with the interior of casing I0 through inlet passages 48 and 49 formed around shaft 42 by tubular members 48' and 49' respectively, which members communicate with the chamber 41 through opposite side plates 45 and 46 and extend outwardly from the walls into the interior of casing I0 parallel to shaft 42. Inlet passages 48 and 49 are controlled by dampers 56 and 5| over the outer end of said passages respectively. The dampers comprise baffle plates which are actuated by shafts 59' and 5| on which the bailies are pivoted at the top respectively so that when the shafts are turned in one direction the bafiies move outwardly at the bottom thereof away from the passage to open them and when turned in the opposite direction move inwardly at the bottom thereof toward said passages to close them. Shaft 42 is mounted at the opposite ends thereof in bearings 52 and 53 respectively which bearings are positioned in casing II].

The top plate I2 of casing I0, as shown in Fig. l, is curved at 54 on a horizontally extending axis which extends in a horizontal plane transversely of the axis of rotation of shaft 42.

Inlet passages 48 and 49 are in communication with the atmosphere outside of casing I6 respectively through vertically extending auxiliary air supply passages 55 and 56, the inlet openings of which are in top plate l2. Passages 55 and 56 are controlled respectively by dampers 51 and 58.

Pulverized material is classified by passing said material upwardly through classifying chutes 59 and 60 along the opposite sides of plates 45 and 46 of housing 43. Chutes 59 and 60 are formed at the outer side thereof by vertically extending plates 6| and 62 and on the inner side by side plates 45 and. 46 of the exhauster housing. The chutes are closed at one end between side plates 45 and 46 by a plate of feed chutes 34 and 35 and at the opposite end by the inner periphery of casing I0 and extend from a point above the ring assembly to a point in spaced relationship with curved portion 54 of top plate I2. Plates 6| and 62 have inclined portions 63 and 64 which are a eeaeee 5 inclined inwardly toward the ring assembly, while the chutes 59 and 60 have inlets 65 and 66 above the inclined portions and the ring assembly and outlets 61 and 65 at the upper part of the chutes in spaced relationship to curved portions 54 of top plate 12. Reject passages 65 and 10 are formed laterally of plates 6! and 62 and between said plates and the inner periphery of casing I respectively. Passages 69 and 10 extend at one end thereof vertically adjacent feed chutes 34 and 35 and at one side thereof laterally along classifier chutes 59 and 60 and have inclined bottom plates 1| which direct the rejected material into crushing compartments 30 and 3|.

The main supply of air for the fluid carrying stream enters the chambers within casing l0 through inlet conduit 12 which supply of air-is regulated by dampers 13. Air entering casing I0 through conduit 12 may be heated to dry wet materials being pulverized or cooled to prevent overheating of materials as required.

As shown in Fig. l, shafts 20 and 2| of rollers l and I5 respectively, each has a driving gear 14 fixed thereon adjacent one end thereof which gears 14 are enmeshed with a pinion gear 15 on the shaft of a motor not shown, which shaft has a pulley 16 fixed thereon while shaft 42 of the exhauster fan has a pulley 11 fixedly mounted on the end thereof above pulley 16. A belt 18 engages said pulleys. Rotation of the motor shaft will directly drive shafts 20 and 2| through gears 15 and 14 and indirectly drive the exhaust'er fan through pulleys 16 and 11 and belt 18.

In operation, material flows by gravity downwardly through the feed chutes 34 and 35 and into crushing compartment 30 and 3 I. Guillotine gates 36 and 31 are adjusted to admit the material to the desired level in said compartments, the gates when fully opened permitting material to flow into the crushing compartments to a level approximately even with the top of roller 25. The motor drives shafts 20 and 2| and the driving rollers I5 and I6 thereon respectively and also rotates shaft 42 of the exhauster, as hereinbefore described. Rotation of shafts 20 and 2|, as shown more particularly in Fig. '2, is in a clockwise direction as is the direction of rotation of the rings l3 of the ring assembly. Rotation of the ring assembly in a clockwise direction also rotates roller 25 in such direction. As the crusher roller 25 rotates, the lugs on extensions 28-and 29 thereof break up the lumps of material and project the pieces thereof into free space with-- in casing H]. The projected pieces fall back into the crushing compartments, the pool of material therein becoming fine and fluidized by such action. The lugs on extensions 28 and 29 of roller 25 continue to plow through the fluidized pool during the rotation of the roller and thereby sustain the fluidization, cause further disintegration of the material and continuously project fine material into the free space within the casing.

The fluidized material in crushing compartments 30 and 3| overflows therefrom onto the inner peripheral surface of the rings l3 of the ring assembly and is centrifuged and "conducted by centrifugal force in a thin ribbon of material on said inner peripheral surface of the rings in the direction of rotation thereof. The thin ribbon of material on the inner surface of the ring assembly is squeezed between said surface and the double frustoconical shaped peripheral surface [9 of rollers 15, I6 and the surface of roller 25, Figs. 1 to 5. The pressure developed on the ribbon of material forces and squeezes material into V-shaped grooves l3 between adjacent rings l3 thence between the adjacent side surfaces of adjoining rings.

In the form of the-ring and roller assembly shown in Figs. 1 to 5, as material is squeezed between adjacent rings, the rings are moved apart outwardly along the inclined surfaces I 8 of rollers l5 and [6 toward the rims l1 and I8 thereof and along the inclined surfaces of roller toward rims 26 and 21 thereof against the normal tendency of the rings to move laterally downwardly along the inclined peripheral surface toward the center of the assembly due to the shape of the periphery of the rollers. Due to the different inside diameters of the rings l3, said rings rotate at different speeds, the relative rot'ation thereof mulling and rubbing the particles between said rings together until they become extremely fine. The extremely fine material is projected radially from the ring assembly by further material. being squeezed between said rings by the rollers from the ribbon of material. Any material in trough 33 is subjected to breaking up by lugs [4 on rings l3, some ofv the material being dragged around on the periphery of the ring assembly. by said lugs as the assembly rotates. The speed of the circulating material is somewhat less than the circumferential speed of the peripheral lugs on the extensions of the crushing roller and on the rings causes aclassifying action due to centrifugal force which tends to cause the larger pieces in the feed and heavy foreign matter such as, tramp iron, gravel, sand, rock and pyrites to slowly be forced outwardly from the peripheries of the roller and rings to ward trap 19. As the crushable pieces of material in the feed are crushed by the rapid blows from the projections on extensions 28 and 29 of roller 25 and the projections I4 on the rings l3, the crushed pieces work their way to the top of the pool in compartments 30 and 3| to thereafter overflow into the ring assembly while the uncrushable material remains in the bottom of the compartments to thereafter be removed therefrom through a trap 19. In this manner, tramp rock and iron is effectively rejected from the grinding elements.

The fines projected radially from the ring assembly and any fines from compartments 30 and 3| are carried into classifier chutes 59 and 60 by a stream of air which is drawn into casing I0 through inlet conduit 12 by operation of the exhauster which draws air upwardly through inlets 65 and 66 of chutes 6| and'62 outwardly of said chutes through outlets 51 and 68 thence into exhauster chamber 41 through passages 48 and 49 after passing under the lower edges of bafiles 50 and 5|. The stream of air entrains the fines carrying them upwardly through chutes 59 and B0 thereafter discharging them through outlets 61 and 6B of the chute. The stream of air and entrained fines" impinges against curved portion 54 of top plate [2 and is caused to pass downwardly within the casing by the curvature of said liner. The stream of air and entrained fines is again caused to change its direction 'of flow to pass under the lower edge of battles 5| and 52 to enter chamber 41 in exhau'ster housing 43 through damper controlled inlet passages 48 and 49. The changes of direction of flow of the stream of air and entrained material after leaving outlets 51 and 68 of chutes 59 and 60 prior to entering the passages 48 and 49 causes the heavier entrained material to be rejected from the stream. The rejected ioversize material drops-downwardly into crusher compartments 30 and 3| through reject passages 69 and I0. Since the ratio of rejected oversized material to the material fed into compartments 30 and 3I'through chutes 34 and 35 is great, the rejected material, since it has been dried in the air stream, is dry and will therefore blot away free moisture on the surface of the incoming feed and minimize the retarding effect of said moisture in the feed.

Pulverized material of the desired fineness is blown outwardly of exhauster chamber 41 through exhauster outlet80 in the top of the casing. Upon the closing of passages 48 and 49 by dampers 50 and any pulverized material may be scavenged from said passage and the exhauster with dampers 51 and 58 in an open posi tion so that air may pass downwardly through auxiliary air passages 55 and 56 into inlet passages 48 and 49 thence to outlet 80 through chamber 41, said air entraining pulverized material as it flows through the inlet passages and exhauster chamber to the exhauster outlet.

In the embodiment of ring and roller assembly illustrated in Figs. 6 and 9, only one drive roller is shown. The roller I5 is positioned at the top of the ring assembly and is shaped as in the embodiment disclosed in Figs. 1 to 5, that is, with the peripheral surface I9 thereof inclined downwardly from the rims IT to a point in the roller centrally of the rims, as hereinbefore described, so as to normally urge the rings I3 of the ring assembly together. The peripheral surface of the roller 25 in this embodiment'of the invention, however, is so shaped as to normally urge the adjacent rings apart. In the embodiment of roller 25 shown in Fig. 6, the peripheral surface BI is inclined in opposite directions outwardly and downwardly from a central point between rims 26 and 2"! to said rims. With this arrangement, the adjacent rings I3 of the ring assembly are urged together by roller I5 so that material is crushed between the adjacent rings but the rings are urged apart adjacent the bottom of the ring assembly by surface 8| of roller 25 so that the pressure on the material crushed by the adjacent rings is lower than in the embodiment shown in Fig. 5. Urging apart of the rings at the lower portion also causes a forcing together of the rings at the upper portion of the assembly. The rings I3 are all of 'thesame outside diameter and inside diameter.

In the embodiment of the ring and roller assembly shown in Fig. '7, roller I5 is also posi-' tioned at the top of the ring assembly but is cylindrically-shaped and has spaced peripheral grooves 82 therein which grooves are separated by circular projections 83 of greater outside diameter than the grooves 82. Roller 25 has a cylindrically-shaped peripheral surface 84. Adjacent rings 85 and 86 are of different inside diameter but the outside diameter of the rings are the same. The inside diameter of rings 85 is less than the inside diameter of rings 86, the inside diameter of rings 85 being such that the rings aresuspended in grooves 82, while the inside diameter of rings 86 is such that the rings are suspended on projections 83. In this manner, the rings are vmaintained in a spaced relationship with one another and, since rings85 and 86 are of different inside diameters, they are rotated by roller I9 at different rates of speed.

In the embodiment of the ring and roller assembly illustrated in Fig. 8, the peripheral surface I9 of driving roller I5 and the peripheral surface 254'. of 'rolle1 25, are cylindrically-shaped and have cir'cumferentiallyextending rings at the opposite ends thereof. Surfaces I9 and 25 in Fig. 8 respectively have a plurality of laterally adjoining substantially V-shaped grooves 81 extending peripherally of said surfaces with the apices of the grooves extending toward the axis of rotation of the rollers.

While only one driving roller I5 is shown in the embodiments of ring and roller assemblies shown in Figs. 5 to 8, it will be understood that more than one of such rollers may be utilized. Roller 25 in all forms of the invention is of substantial weight so that it will frictionally engage the inner periphery of the ring assembly and apply a pulverizing force by' force of gravity to the material therein and to the material in the crushing compartments. Roller 25' maintains its position at the bottom of the ring assembly and forces the inner periphery thereof and the outer periphery of the driving rollers into engagement;

In the embodiments of the invention shown in Figs. 10 and 11, the'ring and roller pulverizing elements are substantially the same as those illustrated in Figs. 1 to 4. However, the means for causing a stream of air to flow through the casing and the arrangement of various other elements Within the casing is substantially different.

As illustrated in Fig. 10, the lower portion of the casing III has a door 88 opening outwardly adjacent the pulverizing elements. A cylindrically-shaped hopper 89 is disposed on top of the casing I9, which top is open, and extends upwardly therefrom. Hopper 89 has an inclined bottom 98 in communication with feed chutes 39 and 35, the inclined bottom 90 thereof separating hopper portion 89' from an air chamber 9I which communicates with the interior of casing III. Chamber 9| nas'a damper controlled air inlet conduit 92 in communication therewith. A classifier comprising a tubular member 93 extends vertically in chamber 9I in substantial vertical alignment with the ring assembly and has an inlet 94 communicating with said chamber and the interior of casing I9 adjacent the upper portion of the periphery of the ring assembly. Tubular member 93 is partitioned transversely thereof by a, partition plate 95 extending substantially vertically of the tubular member from the inlet 94 to a point short of a curved baffie 96 in the upper portion of the tubular member and also extending substantially diametrically thereof. Plate 95 has a downwardly projecting flange 97 which projects in spaced relationship with the body of the plate. An outlet conduit 98 communicates at one end thereof with the space between flange 9'! and the body of plate 95 intermediate the opposite ends of said space and extends outwardly of hopper 89. At the opposite end, conduit 98 communicates with the whirl chamber of a cyclone separator 99 tangentially thereof. Air is drawn upwardly through the whirl chamber by an exhauster fan I80 which draws air through a filter IIII.

- In operation of the embodiment of the invention shown in Fig. 10, air is drawn through air inlet conduit 92 into chamber 9i and inside casing I9 thereafter to flow upwardly in passage I92 in tubular member 93, impinge on baflie 96 to be turned downwardly in a curved path thereafter to flow outwardly of member 93 through conduit 98 after passing upwardly under the lower edge of flange 91 into the space'between the flange and the-body of partition 95 and into said conduit. The air in flowing from conduit 92 to conduit 98 entrains pulverized material in chamber 9I and in casing I carrying the entrained, material up== Wardly in passage I02 thereafter impinging on baflle 06. Impingement thereof on baiile 96 causes the stream to flow downwardly in passage I02 of tubular member 93. Change of direction of flow of the stream of air and entrained material by bafile 96 and by flange 9'! separates oversized ma terial from the stream which oversized material flows downwardly in passage I02" onto the periphery of the ring assembly. Entrained mate rial is separated from the stream in the whirl chamber of cyclone separator 90, the separated material flowing downwardly through spout I03 into a container I04. Any material not separated from the stream in the whirl chamber is filtered out by filter IOI.

In the' embodiment ofthe invention shown in Fig. 11, a blower I05 is used to create the fluid stream by means of which pulverized material is conducted from the mill. Blower I05 at its outlet communicates with the pulverizing chamber within casing I0 through air inlet I05 which inlet is damper controlled at I01 and is positioned in substantial horizontal alignment with the ring assembly. The classifier'in this embodiment of the invention comprises an upwardly extending projection I08 of the innermost walls of reject chutes 653 and i0 which walls flank the ring assembly, said innermost walls and projections extending at right angles to the axis of rotation of the ring assembly. Projections I00 form a bafile which extends slightly inwardly toward inlet Hit of the blower thence upwardly to a point above the blower inlet. The projections are thence inclined slightly in a direction away from said blower inlet thence downwardly to form a depending flange I00 which flange is in spaced relationship with the portion of the projection I08 which is inclined in a direction away from'the blower inlet. The uppermost point of' projections I08 is in spaced relationship with curved portions 54 at the top of the casing while flanges I09 project downwardly in spaced relationship with the inner periphery of the casing and in vertical alignment with reject chutes 6'9 and I0. Pulverized material outlet IIO communicates with the space between fiange I09 and the inwardly inclined portion of projection I08.

In operation, air is blown by blower I 05 through inlet I06 into casing I0 wherein it entrains pulverized material. The stream of air and pulverized material passes upwardly, impinges against curved portions 54 at the top of the casing where it is deflected downwardly. After being deflected downwardly by the curved portions, the stream changes its direction of how to pass under the lowermost edge of flange I00 into the space between said flange and the upwardly inclined portion of projections I08 and thence outwardly through outlet I I0. The changing of the direction of flow of the stream causes the oversized mate-- rial to be rejected from the stream, said rejected oversized material passing downwardly through reject chutes 8'9 and I0 into compartments SI and 30 respectively. The stream containing material of the desired particle size flows outwardly of casing I0 through outlet IIO.

Although various preferred forms of the invention have been disclosed herein, it is to be understood that changes may be made in the form and relative arrangement of the parts of the apparatus described without departing from the prin ciples of the invention which are not to be limited excepting by the scope of the appended claims.

What is claimed is;

drive roller having a peripheral driving suriace,

a plurality of laterally adjacent rings each separately pendantly mounted upon said roller, the rings having substantially flat contiguous facing surfaces for pulverizing materials therebetween, the inside diameter of the rings and the diamet o t dr n ro er at the po nt of eng gement of ach of said. ri gs with the peripheral driving surface of said drive roller being such that the distance between the axis of rotation f the d v r ller and the po nt o onsagementof s d. driving suriace and said inner p ipheral surfac of. one ring and. the dis an e w en s d a is o r a iohof th drive oller and the po nt of ng ge nt o said. riv ng surace of the roller an d inner p ripheral. sura e f a rin l eral y dja ent said one ri g are u equal, and a. pulv r hs ro l r resting w thin the plurality of rin s at the otto th re.

of so to exert a. downwardly f rce. on he n s, the confi urati n. f th e i eral drivns urface f sa d. driv roller he config r tion of the peripheral s rface of the pu v rizihg l r and said downwardly for e e rt on th rings by sa d pulverizihs ro e ng su h as to intain the rings in par llelism an in grouped. elationship wi h ea h other around the periphral. dr ing surface oisa d driving roller- 2. The apparatus of claim 1 wherein the pul v zi e roller is avity loaded,

3. The appara us of claim, 1 where n paced s are provide on. said ri e r l er nd spac s ar prov ded n said pu vori ne r lle said rims being positioned on the rollers to prevent ateral movement o said ring yond said. r ms- Pulver z appa atu c mp isin r ng and r l r pu verizihs el m nts. having at l t one x dly uppor ed upper dr v roller un ed to rotate on a substantially horizontal axis, said ve ller ha ing a p riph r riving su i a plu ali y of latera ly adja e t rings a h. eparately pendantly mounted upql Said roller, the n s havin substan ally fla con gu u a ing surfaces for pulverizing materials therebee tween, the inside diameter of the rings and the diameter of the driving roller at the point of g nt o each of s ngs with the peripheral driving surf ce f said d ve r l bein u h. hat th dis anc betw en th axis of r ta n f th rive ro ler and the point f. a t of said dri in u aoo and said inn r p ph ral s rface f one in and h i nce between d x s oi rot tion of the drive ro l r a d the po nt of ngagement of said dr vin surface. he r ller and, said inner per pheral u fa e of a r pe l er y adjacent said one rin are unequal, a pulverizing roller resting within the plurality of rings at the. bottom thereof so as to exert a downwardly force on the rings, the

configuration of the peripheral driving surface f a d d i r l er the configura on f h 11? radially from said extensions in spaced relationship to one another and spaced from one another circumferentially of the extensions.

5. Pulverizing apparatus having a pulverizing chamber, ring and roller pulverizing elements in the chamber comprising at least one fixedly supported upper drive roller having a peripheral driving surface, a plurality of laterally adjacent rings each separately pendantly mounted upon said roller, the rings having substantially flat contiguous facing surfaces for pulverizing materials therebetween, the inside diameter of the rings and the diameter of the driving roller at the point of engagement of each of said rings with the peripheral driving surface of said drive roller being such that the distance between the axis of rotation of the drive roller and the point of engagement of said driving surface and said inner peripheral surface of one ring and the distance between said axis of rotation of the drive roller and the point of engagement of said driving surface of the roller and the inner peripheral surface of a ring laterally adjacent said one ring are unequal, a pulverizing roller resting within the plurality of rings at the bottom thereof so as to exert a downwardly force on the rings, the configuration of the peripheral driving surface of said drive roller, the configuration of the peripheral surface of the pu l verizing roller and-said downwardly force exerted on the rings by said pulverizing roller being such as to maintain the rings in parallelism and in grouped relationship with each other around the peripheral driving surface of said driving roller, driving means for rotating the driving roller, and feeding means for feeding material to.be pulverized to said pulverizing elements, the chamber having a pulverized material outlet.

6. The apparatus of claim 5 wherein the rings have a plurality of lugs on the outer periphery thereof projecting radially therefrom and in spaced relationship to one another circumferentially of the rings.

'7. A pulverizing mill comprising a casing having a substantially vertically extending pulverizing chamber therein, ring and roller pulverizing elements located in the lower portion of the chamber comprising at least one fixedly supported upper drive roller having a peripheral driving surface, the roller being mounted to rotate on a substantially horizontal axis, a ring assembly in spaced relationship circumferentially with the periphery and bottom of the chamber and laterally with said chamber periphery, the ring assembly having a plurality of laterally adjacent rings each separately pendantly mounted upon said roller, the rings having substantially fiat contiguous facing surfaces for pulverizing materials therebetween, the inside diameter of the rings and the diameter of the driving roller at the point of engagement of each of said rings with the peripheral driving surface of said drive. roller being such that the distance between the axis of rotation of the drive roller and the point of engagement of said driving surface and said inner peripheral surface of one ring and the distance between said axis of rotation of the drive roller and the point of engagement of said driving surface of the roller and the inner peripheral surface of a ring laterally adjacent said one ring are unequal, a pulverizing roller resting within the plurality of rings at the bottom thereof so as to exert a downwardly force on the rings, the configuration of the Pe ph driving surface of said drive roller, the configuration of the peripheral surface of the pulverizing roller and said downwardly force exerted on the rings by said pulverizing roller being such as to maintain the rings in parallelism and in grouped relationship with each other around the peripheral driving surface of said driving roller, and feed chutes extending vertically in said chamber and having an inlet adjacent the top and an outlet adjacent the bottom of the chamber, said chutes being disposed in the chamber so as to flank said ring assembly, the chamber having a pulverized material outlet.

8. The apparatus of claim 7' wherein the feed chutes are positioned in the chamber laterally adjoining opposite sides of the ring assembly adjacent the periphery thereof at one side of the chamber with said outlet of each chute disposed so as to face toward the'opposite side of said chamber, and wherein a control damper is associated with the outlet of each chute so as to control the flow of material therefrom, the chamber having a pulverized material outlet in the upper portion thereof.

9. A pulverizing mill comprising a casing having a substantially vertically extending pulverizing chamber therein, ring and roller pulverizing elements disposed in the lower portion of said chamber, said elements having an upper fixedly supported drive roller mounted to rotate on a horizontal axis, a ring assembly in spaced relationship circumferentially with the periphery, and bottom of the chamber and laterally with said chamber periphery the ring assembly having a plurality of laterally adjacent rings each separately pendantly mounted upon said roller, the rings having substantially fiat contiguous facing surfaces for pulverizing materials therebetween, the inside diameter of the rings and the diameter of the driving roller at the point of engagement of each of said rings with the peripheral driving surface of said drive roller being such that the distance between the axis of rotation of the drive roller and the point of engagement of said driving surface and said inner peripheral surface of one ring and the distance between said axis of rotation of the drive roller and the point of engagement of said driving surface of the roller and the inner peripheral surface of a ring laterally adjacent said one ring are unequal,

'a pulverizing roller resting within the plurality of rings at the bottom thereof so as to exert a downwardly force on the rings, the configuration of the peripheral driving surface of said drive roller, the configuration of the peripheral surface of the pulverizing roller and said downwardly force exerted on the rings by said pulverizing roller being such as to maintain the rings in parallelism and in grouped relationship with each other around the peripheral driving surface of said driving roller, extensions of substantially the same diameter as and rotatable with said pulverizing roller, the extensions extending axially from the opposite ends thereof and into the pulverizing chamber, a plurality of lugs projecting radially from said extensions in spaced relationship to one another and extending circumferentially of the extensions, driving means for rotating the driving roller, and feed chutes extending ver-' tically in said chamber and having an inlet adjacent the top and an outlet adjacent the bottom of the chamber, said chutes being disposed in.

the chamber so as to flank said ring assembly,

the chamber having a pulverized material outlet.

u veri g apparatuscomprisin ring and 13 roller pulverizing elements having at least one fixedly supported upper drive roller mounted to rotate on a, substantially horizontal axis, said drive roller having a peripheral driving surface of waisted shape, a group of pulverizing rings comprising a plurality of laterally adjacent rings each separately pendantly mounted upon said roller, the rings having substantially flat contiguous facing surfaces for pulverizing materials therebetween, the inside diameter of the rings of said group of rings decreasing from opposite sides of the group to a point intermediate the opposite sides thereof,and a pulverizing roller resting within the group of rings at the bottom thereof so as to exert a downwardly force on the rings, the pulverizing roller having a peripheral surface of similar waisted shape adapted to frietionally engage the inner peripheral surfaces of the rings so that the rings are maintained in parallelism and grouped toward each other around the peripheral driving surface of said driving roller.

11. The apparatus of claim wherein the ring and roller pulverizing elements have two fixedly supported drive rollers of substantially identical waisted shapes on which the plurality of rings are each separately pendantly mounted.

12. The apparatus of claim 10 wherein the inner peripheral edge of the rings are substantially semi-circular in cross-sectional configuration.

13. The apparatus of claim 10 wherein spaced rims are provided on said drive roller and spaced rims are provided on said pulverizing roller, said rims being positioned on the rollers to prevent lateral movement of said rings beyond said rims.

14. The apparatus of claim 10 wherein the pulverizing roller has axial extensions projecting laterally beyond the group of rings from the opposite ends of the pulverizing'roller, and a plurality of projections extending radially from said extensions in spaced relationship to one another and spaced from one another circumferentially of the extensions.

15. A pulverizing mill comprising a casing having a substantially vertically extending pulverizing chamber therein, ring and roller pulverizing elements disposed in the lower portion of said chamber and comprising two fixedly supported upper drive rollers mounted to rotate on a substantially horizontal axis, said drive rollers each having a peripheral driving surface of substantially identical waisted shapes, a ring assembly comprising a plurality of laterally adjoining rings each separately pendantly mounted upon said rollers, the rings having substantially flat contiguous facing surfaces for pulverizing materials therebetween, the inside diameter of the rings of said group decreasing from opposite sides of the group to a point intermediate the opposite sides thereof, said pulverizing elements being so positioned in the chamber that the ring group is in spaced relationship circumferentially with the periphery and bottom of the chamber and laterally with said chamber periphery, a plurality of lugs on the outer periphery of the rings projecting radially therefrom and in spaced relationship t one another circumferentially of the rings, a pulverizing roller resting within the group of rings at the bottom thereof so as to exert a downwardly force on the rings, the pulverizing roller having a peripheral surface of similar waisted shape adapted to frictionally engage the inner peripheral surface of the rings so that the rings are maintained in parallelism and grouped toward each other around the pean inlet adjacent the top and an outlet adjacent the bottom of the chamber, the chutes being positioned laterally adjoining opposite sides of the ring assembly adjacent the periphery thereof at one side of the chamber with said outlet ofeach'chute disposed so as to face toward the opposite side of said chamber, and a control damper is associated with the outlet of each chute so as to control the flow of material therefrom, the chamber having a pulverized material outlet in the upper portion thereof.

17. A pulverizing mill comprising a casing having a substantially vertically extending pulverizing chamber therein, ring and roller pulverizing elements disposed in the lower portion of said chamber and comprising two fixedly supported upper drive rollers mounted to rotate on a sub stantiallyhorizontal axis, said drive rollers each having a peripheral driving surface of substantially identical waisted shapes, a ring assembly comprising a plurality of laterally adjoiningrings each separately pendantly mounted upon said rollers, the rings having substantially flat contiguous facing surfaces for pulverizing materials therebetween, the inside diameter of the rings of said group decreasing from opposite sides of the group to a point intermediate the opposite sides thereof, said, pulverizing elements being so positioned in the chamber that the ring group is in spaced relationship circumferentially with the periphery and bottom of the chamber and laterally with said chamberperiphery, a plurality of lugs on the outer periphery ofthe rings projecting radially therefrom and in spaced relationship to one another circumferentially of the rings, a pulverizing roller resting within the group of rings at the bottom thereof so as to exert a downwardly force on the rings, the pulverizin roller having a peripheral surface of similar waisted shape adapted to frictionally engage the inner peripheral surface of the rings so that the rings are maintainedin parallelism and grouped toward each other around the peripheral driving surface of said driving rollers, extensions of substantially the same diameter as and rotatable with said pulverizing roller, the extensions extending axially from the opposite ends thereof and into the pulverizing chamber, a plurality of lugs projecting radially from said extensions in spaced relationship to one another and extending circumferentially of the extensions, driving means for rotating the driving roller, and feed chutes extending vertically in said chamber; said chutes each having an inlet adjacent the top and an out let adjacent the bottom of the chamber, the chutes being positioned in the chamber laterally adjoining opposite sides of the ring assembly adjacent the periphery thereof at one side of the chamber with said outlet of each chute disposed so as to face toward the opposite side of said chamber, the chamber having a pulverized material outlet.

18. Pulverizing apparatus comprising ring and roller pulverizing elements having a fixedly supported upper drive roller mounted to rotate on a substantially horizontal axis, said drive roller having a peripheral driving surface of waisted shape, a plurality of laterally adjacent rings each separately pendantly mounted upon said roller,

15 the rings having substantially fiat contiguous surfaces for pulverizing materials therebetween, the inside diameters of the rings being equal, and a pulverizing roller resting within the plurality of rings at the bottom thereof so as to exert a downwardly force on the rings, the pulverizing roller having a crown-shaped peripheral surface adapted to frictionally engage the inner periphmounted on said roller, the rings having substan I tially flat contiguous facing surfaces for pulverizing materials therebetween, the inside diameters of the rings being equal, a portion of the driving roller extending axially beyond the opposite sides of the ring assembly, the peripheral surface of the driving roller decreasing axially thereof from the opposite ends thereof to a point intermediate said opposite ends at substantially the same angle as said decrease of the inside diameter of the rings, the diameter of said extending portion of the driving roller being greater than the diameter of the roller directly adjacent and axially within the ring assembly, and a pulverizing roller resting interiorly of the rings so that the peripheral surface of said roller frictionally engages the inner periphery of the ring assembly by force of gravity and exerts a pulverizing force between said peripheral surface of the pulverizing roller and the inner peripheral sur face of the rings, the peripheral surface of the pulverizing roller decreasing axially from a point intermediate said opposite ends towards said ends, the angle of decrease of the peripheral surface of said pulverizing roller being such as to permit the peripheral surface of the pulverizing roller to frictionally engage the inner peripheral surfaces of the rings.

20. Ring and roller pulverizing elements for a pulverizing mill comprising an upper cylindrically-shaped driving roller fixedly supported to rotate on a horizontal axis and having a plurality of axially spaced circumferentially extending grooves therein, a ring assembly having a plurality of laterally spaced rings suspended on said roller, each separately pendantly mounted on said roller, the rings having substantially flat contiguous facing surfaces for pulverizing materials therebetween, the inside diameter of adjacent rings being different, the inside diameter of one ring engaging the bottom of said groove and the inside diameter of the next adjacent ring engaging the outer peripheral surface of the roller adjoining said groove, and a cylindricallyshaped pulverizing roller resting interiorly of the rings so as to frictionally engage the inner periphery of the ring assembly by force of gravity 16 and exert a pulverizing force between the outer peripheral surface of the pulverizing roller and the inner peripheral surface of the rings.

21. Ring and roller pulverizing elements for a pulverizing mill comprising an upper cylindrically-shaped driving roller fixedly supported to rotate on a horizontal axis and having a plurality of substantially V-shaped circumferentially extending grooves therein, a ring assembly having a plurality of laterally adjacent rings each separately pendantly mounted upon said roller, the rings having substantially flat contiguous facing surfaces for pulverizing materials therebetween, the inside diameter ofthe rings and the diameter of the driving roller at the point of engagement of each of said rings with the peripheral driving surface of said drive roller being such that the distance between the axis of rotation of the drive roller and the point of engagement of said driving surface and said inner peripheral surface of one ring and the distance between said axis of rotation of the drive roller and the point of engagement of said driving surface of the roller and said inner peripheral surface of a ring laterally adjacent said one ring are unequal, and a gravity loaded pulverizing roller resting interiorly of the rings so as to frictionally engage the inner periphery of the ring assembly by force of gravity and exert a pulverizing force between the peripheral surface :of .the pulverizing roller and the inner peripheral surface of the rings, the pulverizing roller being of cylindrical shape, the outer peripheral surface thereof having a plurality of circumferentially extending V-shaped grooves therein similar to said V-shaped grooves in the driving roller. I

MARTIN FRISCI-L GILBERT C. WHITNEY, JR.

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